The bolts go thru the floor of the slide. With 2 people, extend the slide and and back them out. We installed a sofa and I relocated the belts to the outside wall, drilling thru the floor. I also used large washers. I filled the original holes with caulk to keep water out. Thor customer service emailed the floor details for the slide. Call them instead of email, it works better.
I'm wearing trifocals now but my hindsight is 20/20.
Bilsteins and Sumos front and rear...HUGE! FatMat and Hoodliner...HUGE!
Hellwig sway bars F&R, 235/85 Hankook ATM, alignment...HUGE!!!
Battery watering, 260watts Solar and BigFeets to make life easier.